Way back in the early 1980's, I spent a year living with a family in Rouen, France. They taught me French, and how to drink wine mixed with water, and a thousand other things for which I will always remain deeply grateful. On this trip we made a point to visit my host family, and I got to introduce them to Elliot.
Since the last time I was in Rouen, a few things have changed. For one - they cleaned the cathedral. (It use to be black.)
They also installed a metro, and a Bus Rapid Transit system called Le TEOR. We didn't get to ride the metro (Elliot was very disappointed), but we did get to ride the TEOR.
Le TEOR was awesome. Elliot totally approved.
One thing I found interesting: the Rouen metropolitan area has a population density (940 people per square km) which is slightly lower than Palo Alto's.